Way back in August 2010, Nintendo filed a patent for an illumination system, which would seem to work with Wii in some fashion. The item was just published for viewing in the US database today.
Here’s an interesting abstract included with the filing:
An illumination system includes an information processing device capable of communicating with a server via a network and an illumination device capable of receiving a signal from the information processing device. The information processing device includes a reception portion and a lighting control portion. The reception portion receives instruction data from the server, and the instruction data indicates an instruction to cause the illumination device to emit light in accordance with a television broadcast image and/or audio. The lighting control portion outputs a control signal to the illumination device, and the control signal controls lighting by the illumination device based on the received instruction data. The illumination device sheds visible light in accordance with the control signal.
For what it’s worth, the original patent contained drawings in which the Wii is shown. It doesn’t seem like it’d be too tough to bring the tech over to Wii U, though whether Nintendo still has interest in the idea is unknown.